gernally the chinese mags are lighter gray parkerizing, UAGI are dark gray to black. the small little folds, like the baseplate, on a USGI mag are neat and even. on a chinese mag those little folds are not even. also the spot welds down the from are usually not centered well like the USGI are. the edges of the feed lips on the chinese mags are noticably sharper on chinese mags than they are on USGI mags even after being used many times chinese are still sharper.